1 /*
2  * Copyright (c) 2022 Omar Polo <op@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <ctype.h>
18 #include <stdarg.h>
19 #include <stdio.h>
20 #include <stdlib.h>
21 #include <string.h>
22 
23 #include "got_compat.h"
24 #include "tmpl.h"
25 
26 int
27 tp_write(struct template *tp, const char *str, size_t len)
28 {
29 	size_t	 avail;
30 
31 	while (len > 0) {
32 		avail = tp->tp_cap - tp->tp_len;
33 		if (avail == 0) {
34 			if (template_flush(tp) == -1)
35 				return (-1);
36 			avail = tp->tp_cap;
37 		}
38 
39 		if (len < avail)
40 			avail = len;
41 
42 		memcpy(tp->tp_buf + tp->tp_len, str, avail);
43 		tp->tp_len += avail;
44 		str += avail;
45 		len -= avail;
46 	}
47 
48 	return (0);
49 }
50 
51 int
52 tp_writes(struct template *tp, const char *str)
53 {
54 	return (tp_write(tp, str, strlen(str)));
55 }
56 
57 int
58 tp_writef(struct template *tp, const char *fmt, ...)
59 {
60 	va_list	 ap;
61 	char	*str;
62 	int	 r;
63 
64 	va_start(ap, fmt);
65 	r = vasprintf(&str, fmt, ap);
66 	va_end(ap);
67 	if (r == -1)
68 		return (-1);
69 	r = tp_write(tp, str, r);
70 	free(str);
71 	return (r);
72 }
73 
74 int
75 tp_urlescape(struct template *tp, const char *str)
76 {
77 	int	 r;
78 	char	 tmp[4];
79 
80 	if (str == NULL)
81 		return (0);
82 
83 	for (; *str; ++str) {
84 		if (iscntrl((unsigned char)*str) ||
85 		    isspace((unsigned char)*str) ||
86 		    *str == '\'' || *str == '"' || *str == '\\') {
87 			r = snprintf(tmp, sizeof(tmp), "%%%2X", *str);
88 			if (r < 0  || (size_t)r >= sizeof(tmp))
89 				return (0);
90 			if (tp_write(tp, tmp, r) == -1)
91 				return (-1);
92 		} else {
93 			if (tp_write(tp, str, 1) == -1)
94 				return (-1);
95 		}
96 	}
97 
98 	return (0);
99 }
100 
101 static inline int
102 htmlescape(struct template *tp, char c)
103 {
104 	switch (c) {
105 	case '<':
106 		return tp_write(tp, "&lt;", 4);
107 	case '>':
108 		return tp_write(tp, "&gt;", 4);
109 	case '&':
110 		return tp_write(tp, "&amp;", 5);
111 	case '"':
112 		return tp_write(tp, "&quot;", 6);
113 	case '\'':
114 		return tp_write(tp, "&apos;", 6);
115 	default:
116 		return tp_write(tp, &c, 1);
117 	}
118 }
119 
120 int
121 tp_htmlescape(struct template *tp, const char *str)
122 {
123 	if (str == NULL)
124 		return (0);
125 
126 	for (; *str; ++str) {
127 		if (htmlescape(tp, *str) == -1)
128 			return (-1);
129 	}
130 
131 	return (0);
132 }
133 
134 int
135 tp_write_htmlescape(struct template *tp, const char *str, size_t len)
136 {
137 	size_t i;
138 
139 	for (i = 0; i < len; ++i) {
140 		if (htmlescape(tp, str[i]) == -1)
141 			return (-1);
142 	}
143 
144 	return (0);
145 }
146 
147 struct template *
148 template(void *arg, tmpl_write writefn, char *buf, size_t siz)
149 {
150 	struct template *tp;
151 
152 	if ((tp = calloc(1, sizeof(*tp))) == NULL)
153 		return (NULL);
154 
155 	tp->tp_arg = arg;
156 	tp->tp_write = writefn;
157 	tp->tp_buf = buf;
158 	tp->tp_cap = siz;
159 
160 	return (tp);
161 }
162 
163 int
164 template_flush(struct template *tp)
165 {
166 	if (tp->tp_len == 0)
167 		return (0);
168 
169 	if (tp->tp_write(tp->tp_arg, tp->tp_buf, tp->tp_len) == -1)
170 		return (-1);
171 	tp->tp_len = 0;
172 	return (0);
173 }
174 
175 void
176 template_free(struct template *tp)
177 {
178 	free(tp->tp_tmp);
179 	free(tp);
180 }